Luxa2 showed off a handful of its iPhone 4/4S cases at the 2012 International CES, and of the bunch, Carbon Camber ($53) and Lille ($25) both stuck out. The first is a hard plastic case that's reinforced with real carbon fiber under a raised layer of clear plastic -- an interesting change from the numerous faux carbon fiber cases we've seen in the past. Instead of a flat back, this case has a raised rear surface to provide a more comfortable grip. On the other hand, it doesn't provide any button or port protection, as the top and bottom edges are both fully exposed, as is the left side from the side switch to the volume buttons. Lille is even more unique: it's set up as a folio style case with a synthetic plastic exterior. Instead of a proper case, however, it holds the iPhone's back in place with adhesive that lines the inside of the right side. The front cover -- which can be held shut with a magnetic flap -- has openings for the earpiece as well as the portion of the display that shows the caller ID and "Slide to Answer" message, meaning frequent phone users can answer phone calls without having to open the lid. Again, there's no button or port coverage, and unfortunately, this one leaves the Apple logo exposed. While neither of these cases is strictly mainstream, each design has some interesting ideas on how to appeal to specific niches of iPhone 4/4S users.

Editors' Note: iLounge only reviews products in "final" form, but many companies now change their offerings - sometimes several times - after our reviews have been published.
This iLounge article provides more information on this practice, known as revving.